(1R,5S,9S,10R,12R,14R)-14-hydroxy-5-(1-methoxyethenyl)-11,11-dimethyl-2-oxatetracyclo[7.5.0.01,5.010,12]tetradec-6-en-3-one 以
1,4-二氧六环 为溶剂,
以44%的产率得到(1R,5S,6R,8R,10R,11R,15S)-15-methoxy-7,7,15-trimethyl-12,16-dioxapentacyclo[8.4.2.01,11.05,11.06,8]hexadec-2-en-13-one